IMO like everything else the more you educate yourself the more you help yourself. I don’t watch YT to fix my swing, I use it for training ideas, learn about swing mechanics and things like that. There are some YT people, for me like MrShortGame, that I can’t watch, but it’s just me some people love him. Top speed golf clay Ballard had a tip that just clicked with me and I can now diagnose and fix quickly on my big push slice and releases the club head.
I know a good teacher would advance my game miles however and like others have said is generally the best option. My problem is I have looked into teachers in my area and they don’t get the best ratings and driving a long distance for lessons is tough at this time.
Great option, video yourself! You see the problems on YT and you if you have educated yourself a little you’ll see the big issues quickly.